The School of Chemical Sciences (SCS) proposes the purchase of a new console and probes for an eight year old General Electric GN500 MHz solutions NMR spectrometer. The present proposal will support the research of fifty-six faculty members in SCS, four of whom have been identified as primary users: Kenneth L. Rinehart, Peter A. Petillo, John A. Katzenellenbogen, and Steven C. Zimmerman. Other minor users are: Robert C. Coates, Jeffrey S. Moore, and Scott E. Denmark. The studies being undertaken are detailed in section 2C, and include the characterization of new materials isolated from natural products, including antitumor agents, antibiotics, antifungal agents, and immunomodulators; the study of protein-carbohydrate interactions, including the structure determination of designed carbohydrate binding domains and motional studies; the development of receptor-based imaging agents, interactions of carbon-13 labeled steroids, steroid analogs, and peptides with the hormone binding site in steroid receptors; the stereochemistry of reactions involved in terpene and sterol biosynthesis; and the determination and design of new reactions based on chiral phosphorus-stabilized anions. All of these studies have an inherent and large FTNMR component and require state-of-the-art instrumentation. We propose purchasing a three channel Varian Unityplus 500 spectrometer console, with pulse field gradient module, waveform generation on all three channels, a triple resonance 1H(13C/15N) gradient probe, and a micro 1H/13C probe. The new console and probes for the 500 MHz spectrometer will provide greater sensitivity than is currently available on the instrument and, more importantly, will allow the use of modern inverse detection and gradient techniques that are crucial for obtaining 13C NMR spectra from very small samples, for suppression of 1H NMR signals due to the solvent in dilute samples of complex organic molecules, and for studies of the structure, internal motion, and diffusion of polymers in solution. The new probes and console will also provide shaped pulse capability that is integral to all triple resonance experiments, as well as being necessary for selective versions of many 2D experiments, such as selective INADEQUATE for establishing specific carbon-carbon connectivities. The gradient and shaped pulse components offer capability not available anywhere on the Univ. of Illinois campus. The research projects of the users clearly demonstrate a requirement for all of these capabilities.